Sound-amplifying horn



Jan. 3, 1928. 1,655,385

G. W. BULLEY S OUND AMPLIFYING HORN Filed June 19. 1926 Inven'rm" 665M265 605.551

Patented 3, 19255, UNlTilfiD VI. B'ULLEY, 01* 5353016, (EH10, ASSIGNOB/ 33G MILLER CQRPOEATIGEI OF OHIO.

0F AKRON, DI-10, A

u COMPANY,

original application filed February 8, 1926, Serial l lo. 86,869.

My present invention relates to improvements in sound amplifying horns such as are used for radio loud speakers and kindred purposes, and concerns aarticularly horns which are made of lnrd vulcanized rubber, though not limited in all its aspects to this particular material.

In the manufacture of such horns it has been customary to forrn a hollow biscuit of unvulcanized sheet rubber of approximately the shape of the desired horn and place this in amold having an internalcavity of the desired shape, and sub ect to a vulcanizing heat while at the same t me expanded by fluid pressure supplied by the volatilization of a blowing agent inserted within the biscuit, the pressure of the fluid from the blowing agent forcing the material against the walls of the mold, where it be comes vulcanized to the consistency of hard rubber.

In order to confine the gas in such an article during manufacture, it is necessary to provide a blow-over at each end thereof, or in other words, a closed end which must be removed after the molding of the article.

It is also necessary that the neck of the horn shall be provided with means for connection to the loud speaking device. The commercial types of loud speaking devices dilfer materially in size, which requires that the standard types and sizes of horn shall be manufactured each with large variations in the neck connections, which neck connections must be firmly attached to the horns so that no air leaks take place at the point of connection to the loud speaking device.

The present invention aims to provide a method and means whereby a metal ferrule may be rigidly attached to the neck of the horn during the manufacture in such a manner as to support the blow-over and retain the fluid pressure, and in which such blow over may be readily bored out to secure the necessary air passage.

The invention aims further to provide means whereby a horn of the standard type or size may be produced with means whereby it may be readily adapted for connection with any one of the various sizes of standard loud speakers, thereby greatly reducing the amount of stock necessary to be produced and carried on hand.

With these and other objects in view, the

Serial No. 11?,168.

Divided and. this application filed June 19,

invention includes the after described, and the appended claims.

In order that my invention may be better understood, reference is made to the accom panying drawing, in which 1- Figure l is sectional view through a horn member as it appears upon the completion of the vulcani 'ation.

Figs. 2 and 2 are sectional views illustrating supplemental and interchangeable nipples for application thereto, and

Fig. 3 is av sectional view illustrating the boring out of the blow-over.

It may be stated at this point thathorns of a large size are customarily made in two sections for convenience in manufacture, due to complication in shape, these sections being known respectively as thegooseneck and the hell, but for small horns the gooseneck, or a part equivalent thereto, would suffice, and for convenience of illustration I have shown in the present drawing only the goose-neck part, which in the present crawin is numbered 1. While the biscuit is in its plastic and unvulcanized condition a metal ferrule 2 is applied to the small end thereof, which metal ferrule has a closed end 2 and is provided with an inwardly swaged portion or portions for interlocking with the rubber neck for rigidly holding the ferrule in place, which interlock is preferably formed in the shape of an inwardly swaged portion 52" which forms an internal annular rib and corresponding external annular groove. The closed end wall 2 cooperates in supporting the blow-over forming material, which is indicated at l.

Preferably the closed end is provided with a central indentation a which serves to accu ately center the boring bit hereinafter referred to. The vulcanization of the horn in the manner described converts the rubber into hard rubber and causes the ferrule to be rigidly secured in the position shown in 1. For cooperating with this ferrule 2 I provide a plurality of ferrules 3 which have cylindrical parts 3, the interior diameter of which accurately fits the external diameter of the ferrule 2, and which are provided with tubular extensions 3* of sizes corresponding to the various sizes or types of commercial loud speakers. Given an order or demand for horns for attachment to a novel article hereinparticularly defined in blow-over 1 are bored out by a suitable drill e, the extension 3 serving as a guide for the drill.

Having thus described my invention, what I claim is 1. A non-metallic sound amplifying horn having a metallic ferrule secured to the small end thereof, and a second ferrule secured to said first named ferrule and provided with a reduced tubularextension.

2. A non-metallic sound amplifying horn having a metallic ferrule encircling thesmall end thereof and secured thereto, a second metallic ferrule encircling said first named ferrule and secured thereto, said second ferrule havinga reduced tubular extension.

3. A non-metallic sound amplifying horn having a metallic ferrule securedto the small end thereof, and provided with an inwardly swaged portion interlocking with the horn material, and a second ferrule encircling the first named ferrule, and having a part pressed into interlocking engagement with the swaged portion of said first named ferrule, said second ferrule having a tubular extention;

i. A non-metallic sound amplifying horn having a metallic ferrule encircling the small end thereof and interlocked therewith, said ferrule having an inturned annular flange overlying the end of the horn, a second metallic ferrule encircling said first named ferrule in interlocking engagement therewith and having an internal annular shoulder abutting the internal annular fiange of the first ferrule and having also a tubular extension.

.5. In combination, asound amplifying horn of hard rubber compound, and a sheet 7 metal ferrule encircling the small end there of, said metal ferrule having an internal annular rib interlocking with the horn material, and a corresponding external annular channel, and a second sheet metal ferrule encircling the first and having an anular depressed portion engaging said external channel. v i

In testimony whereof, I afix my signature.

G ORGE W, BULLEY. 

